UPDATE: President Obama said Thursday the situation on Mt. Sinjar had "greatly improved" as a result of the U.S. military intervention, and he said he did not expect to order an additional rescue operation to save stranded Yazidis.

In a brief statement from Martha's Vineyard, Obama praised the U.S. military for its success in airdropping food and water to the Yazidis and stopping the advance of Islamic terrorists through airstrikes.

The bottom line is that the situation on the mountain has greatly improved, and Americans should be very proud of our efforts. Because of the skill and professionalism of our military and the generosity of our people, we broke the ISIL siege of Mt. Sinjar, we helped vulnerable people reach safety and we helped save many innocent lives.

Because of these efforts, we do not expect there to be an additional operation to evacuate people off the mountain and it’s unlikely that we’re going to need to continue humanitarian airdrops on the mountain. The majority of the military personnel who conducted the assessment will be leaving Iraq in the coming days."

The news came after a small team of U.S. military and civilian officials conducted an assessment of the situation on Mt. Sinjar. Obama did say conditions remain "dire" for other populations in Iraq due to the threats from the Islamic State of Iraq and the Levant, and the U.S. would continue to help "without committing combat troops on the ground."

We will continue airstrikes to protect our people and facilities in Iraq. We have increased the delivery of military assistance to Iraqi and Kurdish forces fighting ISIL on the front lines."

ORIGINAL: A U.S. military operation to evacuate stranded Yazidis on Mt. Sinjar in Iraq is "far less likely" after an assessment team determined that thousands had already escaped the mountain, the Pentagon said Wednesday night.

The group of about 20 personnel, who were accompanied by members of USAID, found that there were "far fewer Yazidis on Mt. Sinjar than previously feared, in part because of the success of humanitarian air drops, air strikes on ISIL targets, the efforts of the Peshmerga and the ability of thousands of Yazidis to evacuate from the mountain each night over the last several days," said Rear Admiral John Kirby, a Defense Department spokesman, in a statement Wednesday.

Kirby noted that the assessment team "did not engage in combat operations" and was returned safely to Irbil by air after its mission.

Defense Secretary Chuck Hagel echoed that statement in comments to reporters at Andrews Air Force Base, and Pentagon officials told The New York Times that a combination of U.S. airstrikes and Kurdish forces had effectively broken the siege of Mt. Sinjar laid by the Islamic State of Iraq and the Levant.

"The situation is much more manageable," one official told The Times. Thousands of Yazidis remained on the mountain as opposed to the tens of thousands who were initially stranded with dwindling food and water, and some of those remaining indicated to Americans they did not plan on leaving.

The assessment occurred quickly and came just hours after Ben Rhodes, the deputy national security adviser, told reporters in Martha's Vineyard that President Obama was considering a rescue mission on Sinjar that could have put U.S. forces on the ground.

Here is the full Pentagon statement from Kirby:

As part of the ongoing humanitarian efforts ordered by President Obama, today a team of U.S. military personnel, accompanied by USAID, conducted an assessment of the situation on Mt. Sinjar and the impact of U.S. military actions to date. The team, which consisted of less than twenty personnel, did not engage in combat operations and all personnel have returned safely to Irbil by military air. The team has assessed that there are far fewer Yazidis on Mt. Sinjar than previously feared, in part because of the success of humanitarian air drops, air strikes on ISIL targets, the efforts of the Peshmerga and the ability of thousands of Yazidis to evacuate from the mountain each night over the last several days. The Yazidis who remain are in better condition than previously believed and continue to have access to the food and water that we have dropped. Based on this assessment the interagency has determined that an evacuation mission is far less likely. Additionally, we will continue to provide humanitarian assistance as needed and will protect U.S. personnel and facilities."

Separately on Wednesday, the United Nations announced that it had declared the humanitarian crisis in Iraq the highest level of emergency after four children were killed in fighting between Iraqi troops and Sunni militants.

The declaration triggers an additional amount of aid to the area, said Nickolay Mladenov, the U.N. special representative for Iraq.

Given the scale and complexity of the current humanitarian catastrophe, this measure will facilitate mobilization of additional resources in goods, funds and assets to ensure a more effective response to the humanitarian needs of populations affected by forced displacements."